Surgical table transfer system

ABSTRACT

A surgical table transfer system comprising a patient support in the form of a table top; a surgical table base in the form of a pedestal; a transporter; and a connection device for selectively connecting the table top to the pedestal or the transporter, the connection device comprising a first transfer block mounted on the pedestal; a second transfer block mounted on the transporter; and a latch mechanism mounted on the table top and adapted selectively to latch with one of the first and second transfer blocks, the latch mechanism comprising a body having first and second opposite mating surfaces, each of which is adapted to mate with a corresponding mating surface of a respective first or second transfer block, and a displaceable catch member mounted on the body which is adapted to be displaceable between first and second latching positions for respective latching engagement with the first and second transfer blocks, the catch member having first and second catch elements on a respective opposite side thereof, each transfer block including a cavity for latching engagement therein of the respective catch element.

The present invention relates to a surgical table transfer system.

It is known to provide a surgical table transfer system for minimisingthe disturbance and handling of patients during their transfer from ahospital bed to a surgical operation table. The handling of patients isminimised partly to minimise trauma to the patient and partly tominimise manual handling by hospital staff.

Such known surgical table transfer systems comprise a patient support inthe form of a table top, defining an upper surface for supporting thepatient, which is removably mounted on a transporter in the form of awheeled trolley which is readily manoeuvrable. The transporter is usedas a support for the surgical table top when used as a hospital bed.When the surgical table top is to be used as a surgical operation table,the surgical table top is removed from the transporter onto a surgicaltable base, also known as a pedestal. The pedestal can be operated so asto adjust the height of the surgical table top for the convenience ofthe hospital staff during the operation.

Such surgical table transfer systems are known for example fromEP-A-0457246 (and its equivalent U.S. Pat. No. 5,083,331) andEP-A-0691117 (and its equivalent U.S. Pat. No. 5,611,638). These knownsystems incorporate trapezoidal connecting elements arranged on theopposed longitudinal side edges of the table top and which dependdownwardly from the table top. The connecting elements may be receivedin complementary trapezoidal shaped receivers in the transporter and thepedestal. In order to provide a latching of the table top to thepedestal as well as to the transporter in order to prevent an unintendedrelease of the table top from the particular support being used at thetime, the connecting elements are each provided with a pair oflongitudinally opposed latching members in the form of pivotallysupported pawls. Each pawl is biased towards an outwardly pivotedposition by a respective helical compression spring. The pawls arearranged to be selectively latched in an associated detent recess in thetransporter or the pedestal. Sensors may be provided to determinewhether each of the latching pawls is latched into its associated detentrecess.

These known mobile surgical table transport systems suffer from theproblem that the attachment devices between the table top on the onehand and the pedestal and the transporter on the other hand arecomplicated in construction, requiring a plurality of moving parts.Furthermore, there is also a need more easily to assist accuratelocating of the table top relative to the pedestal or the transporterduring the transfer operation when the table top is being transferredfrom the transporter to the pedestal or vice versa. Furthermore, despitethe plurality of pawls on each side of the table top, only one pawl actsat any given time to prevent tipping in a given direction. Consequently,the table top can be rendered vulnerable to unintended release by thefailure of a single pawl.

The present invention at least partially aims to overcome these problemswith the prior art. The present invention aims to provide an improvedsurgical table transport system, in particular having a more simplifiedand reliable locking and location mechanism between the table top, thepedestal and the transporter.

Accordingly, the present invention provides a surgical table transfersystem comprising a patient support in the form of a table top; asurgical table base in the form of a pedestal; a transporter; and aconnection device for selectively connecting the table top to thepedestal or the transporter, the connection device comprising a firsttransfer block mounted on the pedestal; a second transfer block mountedon the transporter; and a latch mechanism mounted on the table top andadapted selectively to latch with one of the first and second transferblocks, the latch mechanism comprising a body having first and secondopposite mating surfaces, each of which is adapted to mate with acorresponding mating surface of a respective first or second transferblock, and a displaceable catch member mounted on the body which isadapted to be displaceable between first and second latching positionsfor respective latching engagement with the first and second transferblocks, the catch member having first and second catch elements on arespective opposite side thereof, each transfer block including a cavityfor latching engagement therein of the respective catch element.

Embodiments of the present invention will now be described, by way ofexample only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a surgical table transport systemincluding a surgical table top, shown removably mounted on atransporter, and a surgical table pedestal in accordance with anembodiment of the present invention;

FIG. 2 is a perspective enlarged schematic view, partly in phantom, andin a dissembled configuration, of a pair of transfer blocks forrespective mounting on the pedestal and on the transporter and a latchmechanism for cooperation therewith for mounting on the table top of thesystem of FIG. 1;

FIGS. 3 and 4 are, respectively, plan and front views of the transferblocks of FIG. 2;

FIG. 5 is a front view of one of the transfer blocks when latched withthe catch member of the latch mechanism of the system of FIG. 1; and

FIGS. 6, 7 and 8 are schematic end views, partly in phantom, of thetransfer blocks of the pedestal and the transporter and the latchmechanism on the table top illustrating sequential steps in the transferof the table top from the transporter to the pedestal and vice versa.

Referring to FIG. 1 there is shown a surgical operation table transportsystem, designated generally as 2, in accordance with an embodiment ofthe present invention. The surgical table transfer system 2 comprises asurgical table top 4 which is removably mounted on a wheeled transporter6, otherwise known as a trolley, which is readily manoeuvrable and yetprovides a secure base for the surgical table top 4 when it is used as ahospital bed. The surgical operation table transport system 2 furtherincludes a surgical operation table pedestal 8, also known as a tablebase, which stands on the floor. Typically, a surgical operation tabletransport system normally comprises one pedestal in conjunction with twotable tops and two transporters. The pedestal 8 includes a base portion10, which is provided with wheels or casters (not shown) which providesome limited manoeuvrability to the pedestal 8, and a column 12 ofadjustable height mounted on the base portion 10. The height of thecolumn 12 may be adjusted either hydraulically or electrically. Thetable top 4 is divided into four sections, namely a head section 14, anupper torso section 16, a lower torso section 18 and a leg section 20.Together, the four sections define a patient support surface 22. Thesections 14, 16, 18, 20 can be pivoted relative to each other so as toadjust the relative angle of the sections, and thereby the shape andconfiguration of the patient support surface 22.

An under surface 25 of the upper torso section 16 of the table top hasmounted thereon, on opposite sides thereof, a pair of spaced,longitudinally oriented, downwardly depending latch mechanisms 24 asshown in greater detail in FIG. 2. Each latch mechanism 24 includes acatch member 26 and a catch support member 28. Each catch support member28 has pivotally mounted thereon a respective catch member 26. Eachlatch mechanism 24 is configured selectively to cooperate and latch witha respective longitudinally oriented transfer block 30,32 provided bothon the column 12 of the pedestal 8 and on the transporter 6.

The pedestal transfer blocks 30 are provided on respective oppositelongitudinally directed upper edges 34 of the column 12, so as to belaterally outwardly directed. Conversely, the transfer blocks 32 on thetransporter 6 are longitudinally mounted on respective opposite upperedges 36 of a frame member 38 of the transporter 6 and are laterallyinwardly directed. There are thus provided two pairs of cooperatingtransfer blocks 30,32, each pair 30,32 being on a respective oppositeside of both the pedestal 8 and the transporter 6. A single pair oftransfer blocks 30,32 is illustrated in FIG. 2. Each transfer block30,32 of a pair is adapted to cooperate with a respective opposite side40,42 of latch mechanism 24 which is received between the opposedtransfer blocks 30,32 of the pair when the table top 4 is beingtransferred from the transporter 6 to the pedestal 8 or vice versa.

Referring in detail to FIGS. 2 to 5, the transfer blocks 30,32 mountedon the pedestal 8 and the transporter 6 have the same structure andconfiguration. The transfer blocks 30,32 of each cooperating pair faceeach other in a mirror-symmetrical manner during transfer of the tabletop 4 when the latch mechanism 24 is located between the two transferblocks 30,32. Each transfer block 30,32 includes a longitudinallyoriented elongate backing plate 44 provided with a pair oflongitudinally separated mounting holes 46 by means of which the backingplate 44 is securely affixed, for example by threaded bolts (not shown),to the upper longitudinal edge 36,34 of the respective transporter 6 orpedestal 8. The uppermost face 48 of the backing plate 44 of thetransfer block 30,32 is downwardly and forwardly chamfered to provide aninclined surface 48, typically inclined at an angle of 45° to thehorizontal. At the centre of the backing plate 44 is provided anintegral forwardly directed chamfered extension 50 defining a pair offorwardly directed opposed side faces 52,54 and therebetween adownwardly and forwardly directed lower inclined face 56 which istypically inclined at an angle of 75° to the horizontal. In addition, atthe centremost part of the inclined face 56 is provided an integralforwardly-directed trapezoidal or wedge shaped support member 60.

The trapezoidal support member 60 includes two opposite side faces 62,64which are each inclined to the vertical, typically at an angle of 15°,so as to define an upwardly pointing trapezoidal shape, with the upperand lower edges of the trapezoidal shape being defined by a planar upperhorizontal surface 66 and an opposite planar lower horizontal surface 68of the trapezoidal support member 60. The lower surface 68, andcorrespondingly a lower part of each of the two opposite side faces62,64, are disposed below a bottom edge 70 of the backing plate 44. Thefront face 72 of the trapezoidal support member 60 consists of adownwardly and forwardly inclined upper surface 74, typically inclinedat an angle of 45° to the horizontal, and a vertical lower surface 76defining the major portion of the front face 72 of the trapezoidalsupport member 60. A lower part of the vertical surface 76 is providedwith one or more inwardly recessed horizontally oriented elongaterecesses 78.

Each transfer block 30,32 is provided with one or more longitudinallyspaced downwardly extending cylindrical bores 80,82 which extenddownwardly from the planar upper surface 66 of the trapezoidal supportmember 60. As shown in FIGS. 6 to 8, a compression sprung element 84 isreceived in each bore 80,82, the upper end 96 of each sprung element 84extending, in the relaxed configuration, above the planar upper surface66.

Each latch mechanism 24 which is mounted on the under surface 25 of thetable top 4 includes a horizontal longitudinally oriented elongatebacking plate 100 having respective mounting holes 102,104 at theopposite longitudinal ends thereof for securely fixing the latchmechanism 24 to the table top 4 by means of, for example, threaded bolts(not shown). Each longitudinally directed face 106,108 of the backingplate 100 is downwardly and inwardly inclined so as to be matable withthe correspondingly inclined uppermost face 48 of the backing plate 44of each transfer block 30,32.

At the longitudinal centre of the backing plate 100, is disposed adownwardly directed catch support assembly 110 comprising a pair oflongitudinally spaced catch support members 112,114 with a movable catchmember 26 being disposed therebetween. The longitudinally outwardlyfacing surfaces 116,118 of the two catch support members 112,114 arevertical. The longitudinally inwardly facing opposed surfaces 120,122 ofthe two catch support members 112,114 are downwardly and outwardlyinclined relative to the vertical so as to define therebetween atrapezoidal, or wedge shaped, recess 123 for mating reception therein ofthe trapezoidal support members 60 of the transfer blocks 30,32, each ona respective side of the recess 123. Typically, the surfaces 120,122 areinclined at an angle of 10° to the vertical.

The pair of longitudinally directed, laterally facing, faces 124,126 ofeach catch support member 112,114 each include a major upper inclinedportion 128 and a minor lower inclined portion 130 which together forboth faces 124,126 define a downwardly pointed tip 132 of each catchsupport member 112,114. The two opposite upper inclined portions 128 areboth downwardly and inwardly inclined, typically at an angle of 15° tothe vertical, and the two opposite lower inclined portions 130 are alsodownwardly and inwardly inclined typically at an angle of 45° to thevertical, so as to terminate in the pointed tip 132 of the catch supportmember 112,114.

The catch member 26 is longitudinally mounted in the recess 123 andpivotally mounted about a longitudinally directed axis 134 extendingbetween the opposed facing surfaces 120,122 of the catch support members112,114. The catch member 26 is freely pivotally mounted and is unbiasedin any particular direction. The catch member 26 has a substantiallyT-shaped cross-section, with a pair of opposite outwardly directed arms136,138 at the top thereof and an integral centrally downwardlydepending leg 140. The axis 134 is orthogonal to the arms 136,138 andthe leg 140. At the junction of the arms 136,138 and the leg 140 isprovided a longitudinally oriented elongate bore 142 through which anelongate catch pin 144 extends, with the catch pin 144 being securelyaffixed, for example by threaded bolts (not shown), at each end thereofto a respective catch support member 112,114. The catch member 26 can befreely pivoted in a rocking motion about the catch pin 144. Each arm136,138 includes a downwardly facing bearing surface 146,148 which isadapted to cooperate with the upper end of each of the sprung elements84 mounted in the respective transfer block 30,32. The leg 140 of thecatch member 26 is provided with a downwardly pointed arrowhead-sectionfoot 150 at the bottom end 152 thereof including two opposedlongitudinally oriented laterally outwardly facing catch elements154,156, each catch element 154,156 including an upper planar portion158 and a lower downwardly and inwardly inclined portion 160, with eachcatch element 154,156 being shaped and configured so as to be receivedin a respective recess 78 of a transfer block 30,32.

The length, in a longitudinal direction, of the catch member 26 is, forthe upper portion thereof comprising the arms 136,138 and an upper part162 of the leg 140, slightly less than that of the trapezoidal recess123 at the upper edge thereof. The two sides of the leg 140 taperinwardly to provide a reduced width at a lower part 164 of the leg 140.

It will be apparent to those skilled in the art that the shape, geometryand configuration of the various interconnecting or engaging elementsemployed in the present invention may be modified or varied withoutdeparting from the invention.

The operation of the surgical table transfer system in accordance withthe embodiment of the invention will now be described with particularreference to FIGS. 6 to 8.

FIG. 6 schematically shows the transfer block 30, which is one of thepair thereof affixed to the pedestal 8, in the configuration with thetransfer block 30 supporting and being in latching engagement with oneof the latch mechanisms 24 of the pair thereof which are affixed to thetable top 4. As may be seen from FIG. 6, in the latching configuration,the catch element 154 is received within the recess 78 of the transferblock 30 as a result of the upwardly directed bias on the surface 146 ofthe arm 136 by the upper end 96 of the sprung element 84 bearingthereagainst, which, in FIG. 6, urges the catch member 26 in a clockwisedirection. This in turn urges the catch element 154 into the recess 78,which securely latches the table top 4 relative to the pedestal 8, andprevents inadvertent relative vertical movement therebetween.

As shown in FIG. 6, when it is desired to transfer the table top 4 ontothe transporter 6 from the pedestal 8, the column 12 of the pedestal 8is initially raised to a sufficient height so that the transporter 6 canbe manoeuvred beneath the table top 4. The transporter 6 is manoeuvredso that the transfer blocks 30,32 affixed thereto are disposed beneaththe respective latch mechanism 24. There is no need accurately todispose the transfer blocks 30,32 directly underneath the latchmechanism 24, because the provision of the inclined surfaces 48 on thebacking plate 44 of the transfer blocks 30,32 on the one hand and theinclined surfaces 130 and 128 on the catch support members 112,114 onthe other hand permit sliding movement therebetween. This can causerelative lateral movement between the latch mechanism 24 and thetransfer blocks 30,32 which in turn can laterally finely position thetransporter 6 accurately relative to the table top 4 and to the pedestal8. As shown in FIG. 6, when the transfer blocks 32 have been positionedgenerally beneath the latch mechanism 24, the table top 4 is thenlowered by lowering of the column 12 of the pedestal 8 as shown by arrowA.

As shown in FIG. 7, when the latch mechanism 24 is lowered onto thetransfer block 32, the upper end 96 of the sprung element 84 is urgedagainst the bearing surface 148 of the arm 138 which causes compressionof the sprung element 94 from its previously extended configuration.With reference to FIG. 7, this causes anticlockwise movement of thecatch member 26 as the load of the table top 4 is transferred to thetransfer block 32 from the transfer block 30 which is then released oncontinued downward movement of the column 12 as shown by the arrow B.That anticlockwise motion causes the catch element 156 to be latched inthe recess 78 of the transfer block 32. This in turn assures securelatching between the table top 4 and the transporter 6, preventingrelative vertical movement therebetween.

As shown in FIG. 8, on continued downward movement of the column 12 ofthe pedestal 8 and the transfer block 30 mounted thereon in thedirection of arrow C, the table top 4 carried on the latch mechanism 24is released from the pedestal 8 by de-engaging of the transfer block 30from the latch mechanism 24. The table top 4 is accordingly supported bythe transporter 6. When the column 12 of the pedestal 8 has been movedsufficiently downwardly that the transfer block 30 is below the latchmechanism 24, the transporter 6 carrying the table top 4 can be wheeledaway from the pedestal 8.

It will be clear to a person skilled in the art that when it is desiredto transfer the table top 4 from the transporter 6 back onto thepedestal 8, a reverse sequence of steps occurs.

1. A surgical table transfer system comprising a patient support in theform of a table top; a surgical table base in the form of a pedestal; atransporter; and a connection device for selectively connecting thetable top to the pedestal or the transporter, the connection devicecomprising a first transfer block mounted on the pedestal; a secondtransfer block mounted on the transporter; and a latch mechanism mountedon the table top and adapted selectively to latch with one of the firstand second transfer blocks, the latch mechanism comprising a body havingfirst and second opposite mating surfaces, each of which is adapted tomate with a corresponding mating surface of a respective first or secondtransfer block, and a displaceable catch member mounted on the bodywhich is adapted to be displaceable between first and second latchingpositions for respective latching engagement with the first and secondtransfer blocks, the catch member having first and second catch elementson a respective opposite side thereof, each transfer block including acavity for latching engagement therein of the respective catch element.2. A surgical table transfer system according to claim 1 wherein thecatch member has a substantially T-shaped cross-section and comprises apair of opposite outwardly directed arms and a leg, the catch memberbeing pivotally mounted to the body about an axis orthogonal to the armsand the leg.
 3. A surgical table transfer system according to claim 2wherein the catch member is freely pivotally mounted to the body and isunbiased in any particular direction.
 4. A surgical table transfersystem according to claim 2 wherein the catch elements are disposed at afoot at an end of the leg.
 5. A surgical table transfer system accordingto claim 2 wherein the arms of the catch member each define a respectivebearing surface, each bearing surface being adapted to be engaged by arespective transfer block, thereby to be urged upwardly to pivot thecatch member about the axis thereby to latch one of the catch elementsin the cavity of that respective transfer block.
 6. A surgical tabletransfer system according to claim 5 wherein each transfer block isprovided with at least one biasing element which is adapted to be urgedagainst the respective bearing surface to cause pivoting of the catchmember when the respective transfer block supports the latch mechanism.7. A surgical table transfer system according to claim 6 wherein thebiasing element comprises one or more sprung components disposed in abore of the transfer block, an end of the sprung components extending,in an unbiased configuration, above a surface of the transfer block forengagement with the catch member.
 8. A surgical table transfer systemaccording to claim 1 wherein the body defines a trapezoidally shapedrecess in which the catch member is mounted, and each transfer block isprovided with a correspondingly trapezoidally shaped support member formating engagement with the recess.
 9. A surgical table transfer systemaccording to claim 8 wherein the trapezoidal shape of the recess and thetrapezoidal shape of the support members point upwardly.
 10. A surgicaltable transfer system according to claim 1 wherein the body of the latchmechanism includes two downwardly depending longitudinally spaced catchsupport members between which the catch member is mounted, each catchsupport member having a pair of opposite lateral faces which aredownwardly and inwardly inclined, and each transfer block has a pair oflongitudinally spaced lateral faces which are downwardly and outwardlyinclined, the lateral faces of both the catch support members and thetransfer blocks being adapted to permit relative sliding motiontherebetween for assisting lateral location of the transfer blocksrelative to the latch mechanism during relative vertical movementtherebetween.
 11. A surgical table transfer system according to claim 10wherein the inclined lateral faces of the catch support members eachcomprise an upper portion and a lower portion, the lower inclinedportion being inclined at a greater angle to the vertical than the upperportion, and each inclined lateral face of the transfer block comprisesan upper portion and a lower portion, the upper portion being inclinedat a greater angle to the vertical than the lower portion.